A severe illness which affects the red blood cell count has been found

Question

A severe illness which affects the red blood cell count has been found to be hereditary. Fifty percent of those who are diagnosed with the illness have a parent who suffers from it. A known scientist has hypothesized that 50% of the children of carriers of the illness will also suffer from it at one point or another.

Which of the following, if true, would most weaken the conclusion drawn by the known scientist?

Which of the following, if true, would most weaken the conclusion drawn by the known scientist?

A. There are many diseases which are genetic, but few of them show a 100% chance of transferring to one's children.

B. Those suffering from the disease whose parents also suffer from it have, on average, one other sick sibling and three healthy siblings.

C. The illness, though serious, it treatable.

D. The average number of children per woman across the globe is less than 2.

E. If you have the illness, the chance that any specific grandchild of yours will suffer from it is 25 out of 100, considering no-one else in the grandchild's family has the disease.

Bunuel · Accepted Answer

OFFICIAL EXPLANATION

A severe illness which affects the red blood cell count has been found to be hereditary. Fifty percent of those who are diagnosed with the illness have a parent who suffers from it. A known scientist has hypothesized that 50% of the children of carriers of the illness will also suffer from it at one point or another.

Which of the following, if true, would most weaken the conclusion drawn by the known scientist?

Which of the following, if true, would most weaken the conclusion drawn by the known scientist?

A. There are many diseases which are genetic, but few of them show a 100% chance of transferring to one's children.

Incorrect.

To solve this Conclusion Weakening question, first break down the argument. The first two sentences are premises which provide factual data; the last sentence includes a conclusion word (hypothesized) so it's the conclusion:

Premise A: A serious illness is hereditary (carried by genes transferred from parents to children)
 +
Premise B: half of those who have the disease have a parent who also has it
 =
Conclusion: half the children of a parent who has the disease will have it

Possible assumption: the ratio from Premise B, although it refers to a group of sick people only, can be also applied to the ratio of sick to healthy children in a family.

Weakening Data: ?

You are required to find data that weakens the hypothesis that parents give half their children the disease. The correct answer could be one that exposes the argument's assumption.

This answer choice neither weakens nor strengthens the conclusion, as the scientist claimed the disease has a 50% chance of transferring to one's children, rather than 100%. The prevalence of a 100% hereditary disease is irrelevant.

B. Those suffering from the disease whose parents also suffer from it have, on average, one other sick sibling and three healthy siblings.

This answer choice weakens the scientist conclusion by providing contradicting evidence: if the average family of a sick parent has 2 sick children and 3 healthy children, the chances of a parent giving the disease to their children is not 50% (it's 2/5, or 40%).

C. The illness, though serious, it treatable.

Incorrect.

To solve this Conclusion Weakening question, first break down the argument. The first two sentences are premises which provide factual data; the last sentence includes a conclusion word (hypothesized) so it's the conclusion:

Premise A: A serious illness is hereditary (carried by genes transferred from parents to children)
 +
Premise B: half of those who have the disease have a parent who also has it
 =
Conclusion: half the children of a parent who has the disease will have it

Possible assumption: the ratio from Premise B, although it refers to a group of sick people only, can be also applied to the ratio of sick to healthy children in a family.

Weakening Data: ?

You are required to find data that weakens the hypothesis that parents give half their children the disease. The correct answer could be one that exposes the argument's assumption.

The treatability of an illness has nothing to do with the percentage of children of a person with the illness who will inherit it, which is the conclusion you are asked to weaken.

D. The average number of children per woman across the globe is less than 2.

Incorrect.

This answer choice neither weakens nor strengthens the conclusion. The number of children a person has on average doesn't affect the chance of a sick person giving the illness to his child.

E. If you have the illness, the chance that any specific grandchild of yours will suffer from it is 25 out of 100, considering no-one else in the grandchild's family has the disease.

Incorrect.

This answer choice strengthens the conclusion. If 50% of someone's children have the disease, it follows that 25% of those children's children will also suffer from it (considering no-one else has the disease), so this answer choice is consistent with the conclusion, giving it some validity.

swim2109 · Answer

Conclusion: 'Hypothesized that 50% of the children of carriers of the illness will also suffer from it at one point or another.

Weaken the hypothesis

Answer : B. As on avg the number is 40% chance of transferring the disease.

minalgambhir · Answer

CONCLUSION - 50% of the children of carriers of illness would suffer

GIVEN -

1) Illness is hereditary
2) 50% diagnosed with illness have parent who suffer from it

WEAKNER - What new information reduces the belief in the conclusion?

ANSWER CHOICE ANALYSIS -

A) Specifically this illness is not mentioned
B) Siblings - out of scope
C) Doesn't matter to the conclusion
D) Doesn't matter to the conclusion
E) CORRECT

VerbalBot · Answer

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A severe illness which affects the red blood cell count has been found

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